Polyunsaturated fatty acids (PUFA) such as the omega-3 fatty acids are vital to everyday life and function. For example, the beneficial effects of omega-3 fatty acids like cis-5,8,11,14,17-eicosapentaenoic acid (EPA) and cis-4,7,10,13,16,19-docosahexaenoic acid (DHA) on lowering serum triglycerides are now well established. These compounds are also known for other cardioprotective benefits. See e.g., Dyrberg, et al., In: ω-3 Fatty Acids: Prevention and Treatment of Vascular Disease. Kristensen, et al., eds., Bi & Gi Publ., Verona-Springer-Verlag, London, pp. 217-26, 1995; O'Keefe and Harris, Am. J. Cardiology 2000, 85: 1239-41; Radack et al., “The effects of low doses of omega-3 fatty acid supplementation on blood pressure in hypertensive subjects: a randomized controlled trial.” Arch. Intern. Med. 1991, 151: 1173-1180. Indeed, the American Heart Association has also reported that omega-3 fatty acids can reduce cardiovascular and heart disease risk. Other benefits of PUFAs are those related to the prevention and/or treatment of inflammation, neurogenerative diseases, and cognitive development. See e.g., Sugano, Michihiro, “Balanced intake of polyunsaturated fatty acids for health benefits.” J. Oleo Sci. 2001, 50(5): 305-311.
A primary source of many polyunsaturated fatty acids, including omega-3 fatty acids, is fish oil. Diets rich in fish oils are known to have many beneficial effects for heart disease, cancer, arthritis, allergies, and other chronic diseases. (See e.g., The American Heart Association, Scientific Statement, “Fish Consumption, Fish Oil, Omega-3 Fatty Acids and Cardiovascular Disease,” November 2002; Appel et al., “Does supplementation of diet with ‘fish oil’ reduce blood pressure? A meta-analysis of controlled clinical trials.” Arch. Intern. Med. 1993, 153(12):1429-1438; GISSI-Prevenzione Investigators. “Dietary supplementation with omega-3 polyunsaturated fatty acids and vitamin E after myocardial infarction: results of the GISSI-Prevenzione trial.” Lancet 1999, 354: 447-455.)
Some fish oils can contain compounds that may be undesirable for a particular purpose. As such, various methods have been tried in order to remove and/or reduce undesirable compounds from fish oils. For example, distillation has been tried to reduce cholesterol from fish oils but such methods usually require extreme temperature and pressure. Moreover, distillation can produce dark oil and can adversely affect the taste of the oil. Also, distillation can be costly on a commercial scale, and yields are often poor. Other methods involving chemical extractions and/or transformations have also been tried but the expense of reagents and contamination from the chemical extractants, solvents, and reactants can be problematic.
In light of the problems associated with removing undesirable compounds from fish oils, what is needed in the art are methods for removing and/or reducing various compounds from oils. Also needed are oils prepared from such methods (e.g., oils with reduced levels of various undesirable compounds). The subject matter disclosed herein meets these and other needs.